Originally Posted by alabbasi

Check the wiring to the compressor, it may have been setup to bypass the pressure switch which would cause it to run all the time.
If you disconnect the wire and it's still spinning then the shaft may be bent which I've seen to cause this kind of thing.
You know when the compressor is running because the front of the compressor is turning.

Good news is that you can get rebuilt A6 compressors for about $120.